Process and apparatus for spinning metal tubes



Aprifl 17, 1928., 1,666,581

H. E. RAINAUD PROCESS AND APPARATUS FOR SPINNING METAL TUBES Filed May25- 1927 INVENTOR flf zry Z. Rain and Patented Apr. '17, 1928.

UNITED STATES HENRY E. RAINAUD, OF MERIDEN, CONNECTICUT.

PROCESS AND APPARATUS FOR SPINNING METAL TUBES.

Application filed May 25,

This invention relates to spinning metals, and more particularly to aprocess and apparatus for spinning metal tubes into ornamental shapesfor use as furniture legs,

pedestals, electrical fixtures, ca-ndlesticks,

candelabra, lamp arms, and the like.

One object of this invention is to provide a tube spinning machineoperating upon tubular blanks for forming ornamental tubes in a singleoperation without; the necessity of annealing.

A further object is to provide an improved form of mandrel for a tubespinning process, said mandrel being provided with means for locking thetube rigidly thereto.

A further object is to provide a tube spin ning apparatus of the abovenature which will be simple in construction, inexpensive tomanufacture,easy to install and manipulate, compact, and very' efficient and durablein use.

- With these and other objects in view, there.

has been illustrated on the accompanying drawings, one form in which theinvention may be conveniently embodied in practice.

Fig. 1 represents a longitudinal sectional view of the apparatus showingthe tubular blank in position upon the mandrel'before starting thespinning operation.

Fig. 2 is a longitudinal sectional view of the apparatus as it appearswhen the ends of the tubular blank have been spun over into lockedposition upon-the mandrel.

Fig. 3 is a longitudinal sectional view of the apparatus as it appearswhen the tube clamping block and -tail-stock have been assembled inoperating position. T

Fig. 4 is a longitudinal sectional view of the same showing the spinningtool in operating position.

Fig. 5 is a longitudinal sectional view of the same after the spinninghas been completed and the ends of the tube have been cut oft from themandrel preparatory to removal of the tube therefrom.

Fig. 6 is a longitudinal sectional view of the same after the mandrelhas been removed from the head-stock and showing the tail-stock holdingplug in separated relation.

Fig. 7 is a side view of the finished ornamental tube.

In the former methods of making tubular ornamental metallic articles, itwas necessary either to cast the metal by means of a mold and core, tostamp itin a press, or to 1927. Serial No. 194,115.

These former methods were ex gree of skill for their successfuloperation.-

By means of the present invention, the

above and other disadvantages have been avoided. This has beenaccomplished by providing an improved form of tube-hold- 1ng mandrelhaving enlarged portions upon which the ends of a tubular blank areadapted to be locked against rotation, and performing the spinningoperation by pressing inwardly upon the tube with a spinning tool havinga blunt rounded point until the desired ornamental shape has beensecured.

Referring now to the drawings in which like reference numerals denotecorresponding parts throughout the several views, the numeral10indicates an arbor or mandrel preferably constructed from tool steeland having at one end an enlarged cylindrical socket 11 provided withinterior threads 12 to fit over the threaded pin 13 extending from thehead-stock 14 of a lathe, not shown. Adjacent the enlarged socket 11,the mandrel 10 is provided with an enlarged tube-holding flange 15 forsupporting one end of a tubular blank or pipe 16, herein shown ascylindrical, and which may be made of brass, copper, tin, aluminum,zinc, steel, or any other desired metal. The metal to be spun shouldpreferably beso'ft and easily workable, but may be made of hard metal ifonly a small amount of working is to be done upon it.

In order to support the tail-stock end of the tube 16, the mandrel 10has a detachable tube-holding plug 17. said plug having an inwardlytapered conical portion 18 provided with a cylindrical socket 19 fortightly fitting over the tail-stock end 20 of the mandrel 10. The plug17 has an outer shoulder portion 21 for engaging the inside of the end20 of the tube 16 and is reduced in diameter at its outer end 22 fordetachably receiving a cup-shaped clamping block 23. The plug 17 has aninterior bore 24 through which a suitable tool, not shown, may beinserted for facilitating the removal of said plug 17 from the mandrelwhenever desired. The first step in the ornamental tube is to slip thetubular blank 16 over the mandrel and screw the mandrel upon thehead-stock p n 13 in the the operation of spinning position shown inFig. 1. The blank 16 should preferably be of such a size that it will beheld frictionally upon the enlarged flange 15 of the mandrel and theshoulder portion 21 of the tube-holdingplug 17.

The next step of the process is to spin the tail-stock end 26 of theblank 16 around the shoulder 21 of the plug 17 and the headstock end 25around the inner end of the enlarged flange 15. The tubular blank willthen be in the condition as shown in Fig. 2.

The next step in the process is to lock the tubular blank 16non-rotatively upon the mandrel 10 by means of the cup-shaped clampingblock 23. This is accomplished by slipping the socket 27 of saidclamping block 23 over the reduced section 22 of'the tubeholding plug 17until its open end abuts against the inturned end 26 of the tubularblank 16. I y The clamping 'block' 23 will then be forced tightlyagainst the tube end 26 by. moving the tail-stock 28 to the left, asviewed in Fig. 3, by suitable mechanism, not shown, until the blank .16is secured in-non-rotative relation to the mandrel 10. The tail-stock28'has a spherical head 29 for engaging in the recessed end 30 of theclamping block 23, and said head 29 is preferably swiveled in thetail-stock 28.

.The lathe will then be started by applying power to the head-stock 14,as by a pulley,

not shown, and the operation of spinning will be performed by the use ofa suitable spinning tool 31 having a blunt rounded point 32, as shown inFig. 4., the shape of said point depending on the ornamental article tobe'produced. The blunt point 32 of the tool 31 will be pressed inwardlyuponthe tubular, blank16 either with or without the use of a rest orsupporting post, not shown. It will be understood that the workmay-first be laid out upon the tubular blank in pencilor in any othermanner.

After the spinning operation has been completed the inwardly spun ends25 and 26 will be cut off from the finished tube by 7 means of asharp-pointed tool, not shown,

and the tube will then have the appearance illustrated in Fig. 5. p

The tail-stock 28 and clamping block 23 will then'be moved to the right,asviewed in Fig. 5, permitting the tube holding plug 17 and the ring 26on the tail-stock end of the tube 16 to be'det ached from the mandreland slipped out of the finished tube. The

. manrlrel lO may then be readily unscrewed from the head-stock 14, andthe parts will then appear as shown in Fig. 6. The finished tube maythen be slipped off the mandrel 10 and will have the appearance as shownin Fig. 7. The ring 25 of metal on Y the. mandrel 10 between the socket11 and the flange15 may then be removed by cutting pliers or in anyothersuitable manner.

ning the next tubular blank.

During the spinning operation it is pief- ,erable to apply soap, tallow,or beeswax to the tool and blank for lubricating the work and forpreventing the tool from scoring-or cutting the blank. N o coolingliquids, however, are necessary, as the metal does not get hot, any heatwhich maybe developed being rapidly dissipated by the air in the spacebetween the tube 16 and the mandrel 10.

While the invention has been herein disclosed as applied to a tubularblank of cylindrical form, it is to be understood that it is not limitedto that form but that the process may be carrier out equally well upontubular blanks of conical or other shapes.

While' there has been disclosed in this specification one form in whichthe invention may be embodied, it is to be understood that this form isshown for the purpose of illustration'only,and that the invention is not.to be limitedto the specific disclosure but may be modified andembodied in various other; forms without departing from its spirit. Inshort, the invention includes all the modifications and embodimentscoming within the scope of the following claims.

. Having thus fully described the invention, what is claimed as new, andfor which it is desired to secure Letters Patent, is;

1. In an apparatus for spinning ornamental metal tubes, a. rotarymandrel of relatively small diameter adapted to be connected to thehead-stock of a lathe, said mandrel having a pair of enlarged shouldersfor supporting the ends only of a tubular metal blank, said enlargedshoulders being substantially of 'the same diameter as the interior ofthe metalblank, and means for locksaid supported ends may be forcedinwardly by a spinning tool. v

2. In anapparatus .for spinning ornamental metal tubes, a rotary mandreladapted to be-connect'ed to the head-stock of a lathe, said mandrelhaving a pair of en larged shoulders for supporting the ends of atubular metal blank, and means for locking said blank to said mandrelwhereby the metal of said blank between said supported ends may beforced inwardly by a spinning tool, said finished tube being remm ablewithout cutting except outside of said enlarged shoulders. I

3. In an apparatus for spinning orna-- mental xmetal tubes, -a rotarymandrel adapted to be connected to the head-stock of alathe, saidmandrel having a pair of enlarged shoulders for supporting the ends of atubular metal blank, and-means for locking the tail-stock end of saidblank to said mandrel whereby the metal of said blank be ends of atubular metal blank, and means for locking said blank to said mandrelwhereby the metal of said blank between said supported ends may beforced inwardly by a spinning tool, said finished tube being removablewithout cutting except outside of said enlarged shoulders.

- 5. In an apparatus for spinning ornamental metal tubes, a rotarymandrel adapted tobe connected to the head-stock of a lathe, saidmandrel having an enlargedshoulder at its headstock 'end for supportingone end of a tubular metal blank, an enlarged tube holding plug mountedon the tail-stock end ofv said mandrel for supporting the other end ofsaid tubular blank, and a tail-stock engaging clamping block fitted oversaid tube-holding plug for non-rotatively clamping the end vofsaidtube'against said plug,whereby the surface of said blank betweensaid shoulder and plug may be forced inwardly by a spinning tool.

6. The process of spinning an ornamental tube from a tubular metal blankwhich comprises supporting the ends of said blank upon the enlarged endsof a rotary patternless mandrel, locking one end of said blank to saidmandrel, andpressing inwardly upon the outer surface of said blank witha tool having a blunt rounded point. c

7. The process of spinning an ornamenta tube from a tubular metal blankwhich com prises supporting the ends of said blank upon the enlargedends of a rotary patternless mandrel, locking said blank to saidmandrel, and pressing inwardly upon the outer surface of said blank witha tool having a blunt rounded point.

8. The process of spinning an ornamental tube from a tubular metal blankwhich comprises supporting the extreme ends only of said blank uponenlarged portions of a rotary mandrel of smaller diameter than saidtube, locking said blank to said mandrel, and pressing the metal of saidblank inwardly between said enlarged portions.

9. The process of spinning an ornamental tube from a tubular metal blankwhich comprises supporting said blank upon the enlarged portions of arotary mandrel which is of uniform diameter between said enlargedportions, looking said blank to said mandrel, and pressing the metal ofsaid blank inwardly between said enlarged portions.

10. In an apparatus for spinning ornadetachably mental metal tubes, arotary mandrel adapted to be connected to the head stock of a lathe,said mandrel being of relatively small diameter and provided at eitherend' with enlarged shoulders for supporting the ends of a tubular metalblank, one of said shoulders being detachable from the mandrel, andmeans cooperating with the detachable, shoulder for locking the blank inoperable position.

11. In an apparatus for spinning ornamental metal tubes, a rotarymandrel adapted to be connected to the head stock of alathe, saidmandrel being patternless and of relatively small diameter and providedwith an enlargedshoulder near its secured end,

a detachable shoulder mounted on the tail stock end of the mandrel, saidshoulders 00- operating to support atubular metal blank in operableposition on the mandrel but out of contact therewith, and means forlocking the taii stock end of said blank to said mandrel, ,whereby themetal of said blank between the shoulders may be forced inwardly by aspinning tool.

12. In an apparatus for spinning ornamental metal tubes, a rotarypatternless mandrel of relatively small diameter adapted to be connectedto the head stock of a lathe, said mandrel having an enlarged shoulderat its head stock end for supporting one end of a tubular metal blankand an enlarged tube holding plug detachably mounted on the tail stockend of said mandrel for supporting the other end of said tubular blank,said enlarged shoulder of the head stock end of the mandrel and the tubeholding plug being of relatively large di ameter and of substantiallythe same size as the interior diameter of the blank, and a tail .stockengaging clamping means cooperating with the tube holding plug forlocking the blank in operable posi ion on the mandrel, whereby thesurface of said blank between said shoulder and plug may be forcedinwardly by a spinning tool.

13. In'an apparatus for spinning ornamental metal tubes from tubularblanks, arotary mandrel the diameterof which is less than that of theblankto be spun, said mandrel having end shoulders of substantially thesame size as the interior diameter of said blank, means for locking theends of said blank upon said shoulders during the spinning operation,one of said shoulders being removable, there being no obstructions onsaid mandrel to prevent the finished tube from being withdrawn.

14. The process ofspinning an ornamental tube f om a tubular metal blankwhich compris' supporting the ends of said blank upon spaced enlargedends of a rotary III mandrel, spinning the ends of the blank under theouter edges of the enlarged ends ends, locking the tube t0 said mandreland pressing inwardly upon the. outer surface of said tube between theenlarged portions 10 .of the mandrel.

In testimony whereof I have afiixed my signature to this specification.A HENRY. E. RAINAUD.

